Melancholia (7)
I believe the answer is:
sadness
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">melancholia</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sadness that I've seen before include "Gloom" , "Sorrowful quality" , "Melancholy" , "Despondency" , "Dejection" .)